Mohammed Khatami, speaking at the Washington national cathedral on Friday, said that US threats to use force against Iran would not succeed.
"We are in search of solutions. During the course of negotiations we could even talk about suspensions, the nature of suspensions, the timing of suspensions and the durations of suspensions," he said during his unprecedented visit to the US capital.
"I believe that the best recourse [is] to talk and to negotiate over these issues," said Khatami who was the Iranian president from 1997 to 2005.
"The use of force and the threat of use of force, and language of threat have never produced a resolution to this conflict and [such] conflicts."
The UN security council has demanded that Iran suspend its nuclear enrichment by August 31 or face possible sanctions.
Iran, which says its nuclear program is for peaceful purposes, has refused.
In Thursday's meeting, the security council members discussed "the next steps in the [UN] security council" against Iran over its nuclear program, a senior European diplomat said in a clear reference to possible sanctions.
But while Thursday's talks were described as productive, Russia and China were said to still be reluctant to punish Iran for refusing to halt sensitive nuclear fuel work and rejoin international talks.
"We had a first discussion of the next steps in the security council, following the lines of [security council] Resolution 1696," which calls for possible sanctions against Iran, said the diplomat who attended the Thursday meeting.
Iran failed to meet an August 31 deadline, laid out in the resolution, to freeze uranium enrichment, which makes nuclear reactor fuel but also atom bomb material.
Meanwhile, Belarus has joined Russia and China in supporting Iran's nuclear developments on Thursday.
Sergei Martynov, Belarus' foreign minister, said: "Belarus thinks that Iran has every right on every kind of peaceful nuclear activity, in accordance with the non-proliferation regime. We have no grounds to doubt the peaceful nature of Iran's nuclear program."